VR (virtual reality) enables users to enter immersive, virtual environments without leaving the comfort and safety of their physical environments. Users of VR technology can move through virtual spaces and interact with rendered content, such as 3-D (three dimensional) representations of objects, scenery, and other users. At the center of VR technology is the VR headset, which displays images onto opaque screens placed in front of a user's eyes, allowing the user to visualize displayed content in three dimensions. The VR headset typically includes accelerometers and other sensors, which provide input to a 3-D rendering engine, such that the user can change the displayed view of the virtual environment by making natural head movements. The VR headset typically also includes speakers and a microphone, which allow users to hear sounds in the virtual environment and to communicate with others. The user may control a VR application, such as a game, virtual walk-through, or other application using a hand-held controller. A well-known example of a VR headset is the Oculus Rift, available from Oculus VR, LLC.
AR (augmented reality) allows users to continue to see their physical environments through display screens while additional content is superimposed. AR thus provides a vehicle for adding synthetic content to users' normal views of their environments. An example of AR technology is Google Glass.
MR (mixed reality) extends and combines the capabilities of VR and AR by placing synthetic objects at locations referenced to objects in the user's physical environment. An MR headset may scan local surroundings many times per second to learn the locations of walls, ceilings, floors, and objects. As it does so, the MR headset displays holograms via transparent display screens, such that the holograms appear superimposed on objects in the user's natural environment. Displayed holograms may appear stationary in physical space, even as the user moves, or they may move through the environment in natural-looking ways. MR technology thus provides a means for displaying synthetic content alongside actual, physical objects in a user's own physical environment and creates an illusion that the holograms are part of the physical environment. A well-known example of an MR headset is the Microsoft HoloLens, which is available from Microsoft Corporation of Redmond, Wash.